#ifndef COMMON_DATETIMEFORMATTER_H_
#define COMMON_DATETIMEFORMATTER_H_

#include <fermat/common/local_date_time.h>
#include <fermat/common/date_time.h>
#include <fermat/common/date_time_format.h>
#include <fermat/common/format.h>
namespace fermat {


class Timestamp;
class Timespan;

/*!
* This class converts dates and times into strings, supporting a  
* variety of standard and custom formats.
*
* There are two kind of static member functions:
*    * format* functions return a std::string containing
*      the formatted value.
*    * append* functions append the formatted value to
*      an existing string.
*/
class  DateTimeFormatter {
public:
	enum
	{
		UTC = 0xFFFF /// Special value for timeZoneDifferential denoting UTC. 
	};

	/*!
	* Formats the given timestamp according to the given format.
	* The format string is used as a template to format the date and
	* is copied character by character except for the following special characters,
	* which are replaced by the corresponding value.
	*
	*   * %w - abbreviated weekday (Mon, Tue, ...)
	*   * %W - full weekday (Monday, Tuesday, ...)
	*   * %b - abbreviated month (Jan, Feb, ...)
	*   * %B - full month (January, February, ...)
	*   * %d - zero-padded day of month (01 .. 31)
	*   * %e - day of month (1 .. 31)
	*   * %f - space-padded day of month ( 1 .. 31)
	*   * %m - zero-padded month (01 .. 12)
	*   * %n - month (1 .. 12)
	*   * %o - space-padded month ( 1 .. 12)
	*   * %y - year without century (70)
	*   * %Y - year with century (1970)
	*   * %H - hour (00 .. 23)
	*   * %h - hour (00 .. 12)
	*   * %a - am/pm
	*   * %A - AM/PM
	*   * %M - minute (00 .. 59)
	*   * %S - second (00 .. 59)
	*   * %s - seconds and microseconds (equivalent to %S.%F)
	*   * %i - millisecond (000 .. 999)
	*   * %c - centisecond (0 .. 9)
	*   * %F - fractional seconds/microseconds (000000 - 999999)
	*   * %z - time zone differential in ISO 8601 format (Z or +NN.NN)
	*   * %Z - time zone differential in RFC format (GMT or +NNNN)
	*   * %% - percent sign
	*
	* Class DateTimeFormat defines format strings for various standard date/time formats.
	*/
	static std::string format(const Timestamp& timestamp, const std::string& fmt, int timeZoneDifferential = UTC);

	/*!
	* Formats the given date and time according to the given format.
	* See format(const Timestamp&, const std::string&, int) for more information.
	*/
	static std::string format(const DateTime& dateTime, const std::string& fmt, int timeZoneDifferential = UTC);

	/*!
	* Formats the given local date and time according to the given format.
	* See format(const Timestamp&, const std::string&, int) for more information.
	*/
	static std::string format(const LocalDateTime& dateTime, const std::string& fmt);
	
	/*!
	* Formats the given timespan according to the given format.
	* The format string is used as a template to format the date and
	* is copied character by character except for the following special characters,
	* which are replaced by the corresponding value.
	*
	*   * %d - days
	*   * %H - hours	 (00 .. 23)
	*   * %h - total hours (0 .. n)
	*   * %M - minutes (00 .. 59)
	*   * %m - total minutes (0 .. n)
	*   * %S - seconds (00 .. 59)
	*   * %s - total seconds (0 .. n)
	*   * %i - milliseconds (000 .. 999)
	*   * %c - centisecond (0 .. 9)
	*   * %F - fractional seconds/microseconds (000000 - 999999)
	*   * %% - percent sign
	*/
	static std::string format(const Timespan& timespan, const std::string& fmt = "%dd %H:%M:%S.%i");
	
	/*!
	* Formats the given timestamp according to the given format and appends it to str.
	*
	* See format() for documentation of the formatting string.
	*/
	static void append(std::string& str, const Timestamp& timestamp, const std::string& fmt, int timeZoneDifferential = UTC);
	
	/*!
	*Formats the given date and time according to the given format and appends it to str.
	*
	* See format() for documentation of the formatting string.
	*/
	static void append(std::string& str, const DateTime& dateTime, const std::string& fmt, int timeZoneDifferential = UTC);
	
	/*!
	* Formats the given local date and time according to the given format and appends it to str.
	*
	* See format() for documentation of the formatting string.
	*/
	static void append(std::string& str, const LocalDateTime& dateTime, const std::string& fmt);

	/*!
	* Formats the given timespan according to the given format and appends it to str.
	*
	* @See format() for documentation of the formatting string.
	*/
	static void append(std::string& str, const Timespan& timespan, const std::string& fmt = "%dd %H:%M:%S.%i");
	
	/*!
	* Formats the given timezone differential in ISO format.
	* If timeZoneDifferential is UTC, "Z" is returned,
	* otherwise, +HH.MM (or -HH.MM) is returned.
	*/
	static std::string tzdISO(int timeZoneDifferential);
		
	/*!
	* Formats the given timezone differential in RFC format.
	* If timeZoneDifferential is UTC, "GMT" is returned,
	* otherwise ++HHMM (or -HHMM) is returned.
	*/
	static std::string tzdRFC(int timeZoneDifferential);

	/*!
	* Formats the given timezone differential in ISO format
	* and appends it to the given string.
	* If timeZoneDifferential is UTC, "Z" is returned,
	* otherwise, +HH.MM (or -HH.MM) is returned.
	*/
	static void tzdISO(fermat::MemoryWriter& out, int timeZoneDifferential);

		
	/*!
	* Formats the given timezone differential in RFC format
	* and appends it to the given string.
	* If timeZoneDifferential is UTC, "GMT" is returned,
	* otherwise ++HHMM (or -HHMM) is returned.
	*/
	static void tzdRFC(fermat::MemoryWriter& out, int timeZoneDifferential);
};


//
// inlines
//
inline std::string DateTimeFormatter::format(const Timestamp& timestamp, const std::string& fmt, int timeZoneDifferential)
{
	DateTime dateTime(timestamp);
	return format(dateTime, fmt, timeZoneDifferential);
}


inline std::string DateTimeFormatter::format(const DateTime& dateTime, const std::string& fmt, int timeZoneDifferential)
{
	std::string result;
	result.reserve(64);
	append(result, dateTime, fmt, timeZoneDifferential);
	return result;
}


inline std::string DateTimeFormatter::format(const LocalDateTime& dateTime, const std::string& fmt)
{
	return format(dateTime._dateTime, fmt, dateTime._tzd);
}


inline std::string DateTimeFormatter::format(const Timespan& timespan, const std::string& fmt)
{
	std::string result;
	result.reserve(32);
	append(result, timespan, fmt);
	return result;
}


inline void DateTimeFormatter::append(std::string& str, const Timestamp& timestamp, const std::string& fmt, int timeZoneDifferential)
{
	DateTime dateTime(timestamp);
	append(str, dateTime, fmt, timeZoneDifferential);
}


inline std::string DateTimeFormatter::tzdISO(int timeZoneDifferential)
{
	fermat::MemoryWriter out;
	tzdISO(out, timeZoneDifferential);
	return out.str();
}


inline std::string DateTimeFormatter::tzdRFC(int timeZoneDifferential)
{
	fermat::MemoryWriter out;
	tzdRFC(out, timeZoneDifferential);
	return out.str();
}


} 


#endif 
